Search Results (58)

Electronic cigarettes (ECIGs) are widely used but their effects on the immune system need to be further investigated. Macrophages are white blood cells central to the immune response. Using THP-1-derived M0 macrophages, this study aims to determine the effects of ECIG liquids (E-liquids) on the polarization of M0 to the pro-inflammatory M1 macrophage subtype. THP-1 cells were cultured and differentiated to M0 macrophages using RPMI media. E-liquids ± cinnamon, menthol, strawberry and tobacco flavors were added to cell cultures at 1% (v/v) during polarization with lipopolysaccharides and interferon γ for 24 to 72 h. Morphology, viability, gene expression and cytokine production were measured using light microscopy, the LDH cytotoxicity assay, qPCR and ELISA, respectively. The results show that cells present little to no LDH activity under any treatments. In addition, cinnamon-flavored E-liquid severely affects morphology (i.e., abolishing pseudopodia formation), gene expression of all genes tested, and cytokine production. Other E-liquid flavors also affect some of these parameters, but to a lesser extent. Our data suggest that E-liquids can affect the polarization from M0 to M1, thus affecting the immune response in ECIG-exposed tissues such as the mucosa in the oral cavity and airways, ultimately mitigating the health status. Full article

Background: Electronic cigarettes (ECIGs) have grown in popularity, particularly among adolescents and young adults. Flavored ECIG-liquids (E-liquids) are aerosolized by these ECIGs and inhaled into the respiratory system. Several studies have shown detrimental effects of E-liquids in airway tissues, revealing that flavoring agents may be the most irritating component. However, research on the effects of E-liquids on biological processes of the oral cavity, which is the first site of aerosol contact, is limited. Hence, this study focuses on the effects of E-liquid flavors on oral epithelial cells using the OKF6/TERT-2 cell line model. Methodology: E-liquid was prepared with and without flavors (tobacco, menthol, cinnamon, and strawberry). OKF6/TERT-2 oral epithelial cells, cultured at 37 °C and 5% CO₂, were exposed to 1% E-liquid ± flavors for 24 h. Outcomes determined include cell morphology, media pH, wound healing capability, oxidative stress, expression of mucin and tight junction genes, glycoprotein release, and levels of inflammatory cytokines (TNFα, IL-6, and IL-8). Results: Exposure to 1% flavored E-liquids negatively affect cellular confluency, adherence, and morphology. E-liquids ± flavors, particularly cinnamon, increase oxidative stress and production of IL-8, curtail wound healing recovery, and decrease glycoprotein release. Gene expression of muc5b is downregulated after exposure to E-liquids. In contrast, E-liquids upregulate occludin and claudin-1. Conclusions: This study suggests that ECIG use is not without risk. Flavored E-liquids, particularly cinnamon, result in pathophysiological responses of OKF6/TERT-2 cells. The dysregulation of inflammatory responses and cellular biology induced by E-liquids may contribute to various oral pathologies. Full article

Sexual and gender minority (SGM) individuals in the United States are at greater risk for combustible tobacco use and mental health problems compared to heterosexual and cisgender individuals. National data comparing associations of menthol cigarette use and mental health among transgender and cisgender individuals in the United States are lacking. The goals of the current study were to (1) characterize transgender and cisgender individuals who smoke menthol cigarettes, and (2) investigate cross-sectional associations between gender identity, harm perceptions of cigarettes, mental health experiences, and quality of life. Data were drawn from Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study (2018–2019). A total of 3989 cisgender (mean [SD] age, 40.47 [0.32] years) and transgender (mean [SD] age, 38.36 [0.09] years) participants who reported current (past 30-day) menthol cigarette use were included in the analysis. Comparing transgender to cisgender groups, significant differences were found in associations between harm perceptions of cigarettes (adjusted odds ratio [AOR] 0.07; 95% CI: 0.02–0.28) and reported depression (AOR 4.57; 95% CI: 1.36–15.33). Collectively, these findings provide evidence that transgender adults who smoke menthol cigarettes are less likely than cisgender adults who smoke menthol cigarettes to perceive smoking as harmful to health and more likely to report recent experiences of depression. Full article

Background: There is limited evidence on how the United States Food and Drug Administration’s (FDA) proposed ban on menthol cigarettes and flavored cigars will impact individuals with mood disorders who smoke menthol cigarettes. This study aimed to evaluate how individuals with mood disorders who smoke menthol cigarettes might respond to a hypothetical ban on menthol cigarettes, explore the reasons for their current use, and examine how these reasons are associated with participants’ characteristics. Methods: Study data were collected at baseline from adults (18+ years) with mood disorders who participated in a randomized controlled trial evaluating the impact of gradual nicotine reduction. Participants were individuals who smoked and had no plan to quit in the next six months. They reported demographics and tobacco consumption patterns, interest in quitting, and responded to a hypothetical question on a potential ban on menthol cigarettes. The question asked participants which actions they would most likely take if menthol-flavored cigarettes were banned. Means and frequencies were used to describe the sample. Logistic regression was used to determine factors associated with each reason for menthol use (less harmful, better flavor, less harsh on the throat, and less harsh on the chest). Results: Participants (n = 77) were an average age of 42.5 (SD 12.5) years, 61% (n = 47) were female, 68.8% (n = 53) identified as White, and 5.2% (n = 4) identified as Hispanic. On average, participants reported currently smoking 18.1 (SD 9.9) cigarettes per day and had smoked for 23.9 (SD 13.6) years. About 58.4% of participants (n = 45) expressed their intention to switch to non-menthol cigarettes, 19.5% (n = 15) intended to transition to a different type of tobacco product, and 22.1% (n = 17) intended to quit smoking entirely without substitution. The most endorsed reason for using menthol cigarettes was better flavor (89.6%, n = 69/77), followed by less harshness on the throat (41.3%, n = 31/75) and chest (40%, n = 30/75), and the belief that they were less harmful than non-menthol cigarettes (24%, n = 18/75). Older age was associated with the belief that menthol cigarettes were less harmful (OR = 1.06; p = 0.02). Conclusion: Among individuals with mood disorders and who smoke menthol cigarettes and have no plans to quit smoking, 22.1% may try to quit smoking if a menthol ban is implemented, while the majority (58.4%) stated that they would switch to non-menthol cigarettes. As the reasons for using menthol cigarettes included perceived lower harm, there is a need for targeted public awareness campaigns to correct misconceptions about the harms of menthol cigarettes. Full article

New-generation disposable e-cigarettes have become increasingly popular among young adults in the USA since the FDA’s partial flavor ban. This study aims to examine longitudinal changes in health risks among young adults who adopted these novel products, as well as the health effects of device types beyond the effects of other important e-cigarette characteristics. This study recruited e-cigarette users via voluntary response sampling from three college campuses in the USA to respond to four-wave online surveys conducted in four consecutive semesters. Among the participants who adopted disposables during the study, their health risks (dependence symptoms, respiratory symptoms, combustible tobacco use) and e-cigarette consumption characteristics (use frequency, nicotine concentration and flavors) before and after the adoption were compared using paired-sample t- or McNemar’s tests. Generalized linear mixed models with a random intercept were conducted on data from the entire sample to investigate the effects of device type (tank, cartridge/pod, disposable) on health risks, controlling for other e-cigarette consumption characteristics. The study sample of 650 e-cigarette users were, on average, 20 years old, with 49% being male, 70% being White, and 13% being Hispanic. Adopting disposables may increase secondary dependence motives (t = 2.42, p < 0.05) and the use of higher levels of nicotine concentration (t = 2.09, p < 0.05) and sweet flavors (x² = 22.53, p < 0.05) but decrease the number of times of vaping per day (t = −2.18, p < 0.05) and the use of menthol flavors (x² = 4.57, p < 0.05). Tank use is associated with a higher level of primary dependence motives (b = 0.1998, p < 0.05) and a greater odds of using combustible tobacco (b = 0.4772, p < 0.05). Although disposable use is not associated with the likelihood of using combustible tobacco, it is associated with higher levels of both primary (b = 0.2158, p < 0.05) and secondary (b = 0.2533, p < 0.05) dependence motives. It is not the device type, but rather the frequency of vaping, that affects respiratory symptoms (b = 0.0602, p < 0.05). The findings indicate that when young adults switch to disposables, their e-cigarette dependence and use of sweet-flavored e-liquids increase. Even after controlling for use frequency, nicotine concentration and flavors, using disposables is related to not only instrumental motives that are influenced by psychological and environmental contexts but also heavy, automatic use that can operate without environmental cues. Given the health risks associated with disposable e-cigarettes, more comprehensive tobacco product regulations that consider the impact of device types may be needed. Full article

This study investigates the application of an eNose (electrochemical sensory array) device as a rapid and cost-effective screening tool to detect increasingly prevalent counterfeit electronic cigarettes, and those to which potentially hazardous excipients such as vitamin E acetate (VEA) have been added, without the need to generate and test the aerosol such products are intended to emit. A portable, in-field screening tool would also allow government officials to swiftly identify adulterated electronic cigarette e-liquids containing illicit flavorings such as menthol. Our approach involved developing canonical discriminant analysis (CDA) models to differentiate formulation components, including e-liquid bases and nicotine, which the eNose accurately identified. Additionally, models were created using e-liquid bases adulterated with menthol and VEA. The eNose and CDA model correctly identified menthol-containing e-liquids in all instances but were only able to identify VEA in 66.6% of cases. To demonstrate the applicability of this model to a commercial product, a Virginia Tobacco JUUL product was adulterated with menthol and VEA. A CDA model was constructed and, when tested against the prediction set, it was able to identify samples adulterated with menthol 91.6% of the time and those containing VEA in 75% of attempts. To test the ability of this approach to distinguish commercial e-liquid brands, a model using six commercial products was generated and tested against randomized samples on the same day as model creation. The CDA model had a cross-validation of 91.7%. When randomized samples were presented to the model on different days, cross-validation fell to 41.7%, suggesting that interday variability was problematic. However, a subsequently developed support vector machine (SVM) identification algorithm was deployed, increasing the cross-validation to 84.7%. A prediction set was challenged against this model, yielding an accuracy of 94.4%. Altered Elf Bar and Hyde IQ formulations were used to simulate counterfeit products, and in all cases, the brand identification model did not classify these samples as their reference product. This study demonstrates the eNose’s capability to distinguish between various odors emitted from e-liquids, highlighting its potential to identify counterfeit and adulterated products in the field without the need to generate and test the aerosol emitted from an electronic cigarette. Full article

Heated tobacco products (HTPs) are newly developed nicotine delivery systems via the inhalation of mainstream aerosols generated during the heating of tobacco leaf materials. Previous studies have shown that the amount of chemicals generated is much lower than that generated by conventional combustible cigarettes. However, little attention has been paid to formate, a conjugated base of formic acid with potentially toxic effects on human health. This study aims to understand the actual emission levels and behaviour of formate in mainstream aerosols produced by commercially available HTP devices in Japan. Aerosols were generated from four types of devices with regular and menthol-type flavours using a vaping machine following the CRM 81 puffing protocol. Formate was tapped in 5 mM sodium carbonate solution and subsequently analysed using ion chromatography. The results showed that the total emission amount of formate ranged from 0.0027 ± 0.0031 to 0.27 ± 0.055 mg L⁻¹, varying with heating temperature and flavour type. Moreover, the majority of formate existed in a particulate form due to the weak-basic property of the aerosol, and the formate emission level was much greater than the workplace exposure limit for the direct inhalation of mainstream aerosols. The formate in the mainstream aerosol can be considered a health concern, when using “high-temperature type” HTPs over a long period. Full article

The increasing use of e-cigarettes (ECs) has raised public health concerns due to the observed cytotoxic effects in both in vitro and in vivo studies. Infants and young children, being particularly vulnerable groups, exhibit heightened susceptibility to potential hazards arising from maternal use of ECs, as well as exposure to second-hand and third-hand aerosols emitted by ECs. Melanocytes are neural-crest-derived cells that regulate multiple biological functions. Melanocyte death, triggered by chemical exposure, is a known etiological cause of pigmentation abnormalities and neurodevelopmental disorders. Prior reports have demonstrated nicotine-induced differential cytotoxicity to neonatal human melanocytes derived from lightly pigmented (LP) and darkly pigmented (DP) donors. We recently reported that the vehicle base propylene glycol (PG) in e-liquid can alter the functions of LP melanocytes. However, to date, the effects of e-liquid flavors on LP and DP cells remain unexplored. Hence, in this preliminary study, a panel of twenty EC refill liquids comprising ten popular flavors (strawberry, grape, banana, vanilla, butterscotch, cinnamon, menthol, chocolate, cola, and tobacco), where each flavored e-liquid contained either 0 or 18 mg/mL nicotine, was examined for in vitro cytotoxicity to neonatal human melanocytes derived from LP and DP donors. Our results reveal that of the ten flavors, five (menthol, cinnamon, vanilla, tobacco, and banana) were highly cytotoxic, with their half-maximal inhibitory concentration (IC₅₀) values within the tested concentration ranges. Moreover, the cytotoxicity of the specific flavors menthol, cinnamon, and vanilla was enhanced in the presence of nicotine, indicative of interactive effects, with nicotine and flavor contributing to greater melanocyte injury. The cytotoxicity of menthol (both with and without nicotine) and cinnamon (without nicotine) e-liquids was found to be higher in LP cells as compared to DP cells. In contrast, nicotine-containing vanilla e-liquid induced higher cytotoxicity in DP cells than LP cells. Only three flavors, cola (without nicotine), strawberry (without nicotine), and chocolate (without nicotine), were non-cytotoxic to both LP and DP cells. The findings that popular flavors in e-liquids induced moderate to high degree of melanocytotoxicity even in the absence of nicotine suggests that ECs are not harmless. This information may assist EC users identify particular flavors in refill liquids that may be detrimental to melanocytes. A first-screen identification of flavors in e-liquids that show a racial/ethnicity dependence can provide a baseline to identify cytotoxicity concentration ranges for popular flavors and help inform the regulatory guidelines for EC toxicity to young children and youth. Full article

Heated Tobacco Products (HTPs) purport to reduce exposure to tobacco-related toxicants compared to combustible cigarettes. This cross-sectional study examined the content of nicotine, two humectants (propylene glycol (PG) and vegetable glycerin (VG)), and four tobacco-specific nitrosamines (TSNAs: NNN, NNK, NAT, and NAB) in the tobacco filler of a popular HTP brand (IQOS). Non-menthol and menthol IQOS sticks were purchased from nine countries between 2017 and 2020 and were classified into two versions (“Bold” and “Light”) using Philip Morris’s flavor descriptors. The average nicotine concentration was 4.7 ± 0.5 mg/stick, and the highest nicotine concentration was found in products from Japan (5.1 ± 0.2 mg/stick). VG was the dominant humectant found in all sticks, with an average concentration of (31.5 ± 2.3 mg/stick). NNN, NNK, and NAT were substantially higher in the “Bold” sticks than the “Light” sticks. Significant differences between countries for TSNAs were also observed: the NAT and NAB contents were the highest in the “Light” products from Canada (192.5 ± 24.1 and 22.9 ± 1.0 ng/stick, respectively); the NNK concentration was the highest in the “Bold” products from Poland (64.8 ± 7.9 ng/stick); and the highest NNN concentrations were observed in the “Bold” products from South Africa (488.9 ± 26.7 ng/stick). As NNN and NNK are known human carcinogens, and as humectants like PG and VG can degrade into toxic carbonyl compounds upon heating, monitoring the concentration of these chemicals in HTPs is important for protecting users’ health and ensuring compliance with regulations. Full article

Assessment of in vitro cytotoxicity is an important component of tobacco product toxicological evaluations. However, current methods of regulatory testing involve exposing monolayer cell cultures to various preparations of aerosols from cigarettes or other emerging products such as electronic nicotine delivery systems (ENDS), which are not representative of human exposure. In the present study, a whole aerosol (WA) system was used to expose lung epithelial cultures (2D and 3D) to determine the potential of six Vuse Alto ENDS products that varied in nicotine content (1.8%, 2.4%, and 5%) and flavors (Golden Tobacco, Rich Tobacco, Menthol, and Mixed Berry), along with a marketed ENDS and a marked cigarette comparator to induce cytotoxicity and oxidative stress. The WA from the Vuse Alto ENDS products was not cytotoxic in the NRU and MTT assays, nor did it activate the Nrf2 reporter gene, a marker of oxidative stress. In summary, Vuse Alto ENDS products did not induce cytotoxic or oxidative stress responses in the in vitro models. The WA exposures used in the 3D in vitro models described herein may be better suited than 2D models for the determination of cytotoxicity and other in vitro functional endpoints and represent alternative models for regulatory evaluation of tobacco products. Full article

Proteases such as neutrophil elastase cleave and activate the epithelial sodium channel (ENaC), causing airway dehydration. Our current study explores the impact of increased protease levels in vapers’ airways on ENaC activity and airway dehydration. Human bronchial epithelial cultures (HBECs) were exposed to bronchoalveolar lavage fluid (BALF) from non-smokers, smokers and vapers. Airway surface liquid (ASL) height was measured by confocal microscopy as a marker of hydration. ENaC cleavage was measured by Western blotting. Human peripheral blood neutrophils were treated with a menthol-flavored e-liquid (Juul), and the resulting secretions were added to HBECs. BALF from smokers and vapers significantly and equally increased ENaC activity and decreased ASL height. The ASL height decrease was attenuated by protease inhibitors. Non-smokers’ BALF had no effect on ENaC or ASL height. BALF from smokers and vapers, but not non-smokers, induced ENaC cleavage. E-liquid-treated neutrophil secretions cleaved ENaC and decreased ASL height. Our study demonstrated that elevated protease levels in vapers’ airways have functional significance since they can activate ENaC, resulting in airway dehydration. Lung dehydration contributes to diseases like cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD) and asthma. Thus, our data predict that vaping, like smoking, will cause airway surface dehydration that likely leads to lung disease. Full article

The heated tobacco product (HTP) heats rather than burns tobacco to release an aerosol with significantly fewer toxicants than conventional cigarette smoke and has received global attention in recent years. To investigate whether changes in biomarkers of exposure could be detected after switching from conventional cigarettes (CCs) to HTPs, 224 subjects from four cities in China participated in this study. Nine biomarkers containing tobacco-specific nitrosamines (TSNAs), volatile organic compounds (VOCs), and the biomarkers for acrolein and crotonaldehyde were determined by UPLC-MS/MS. The levels of the sum of nine biomarkers in CCs were 5.4 and 5.2 times higher than in an Original-HTP and Menthol-HTP, respectively. Among the nine biomarkers, 3HPMA and 3HMPMA accounted for the highest proportions. Switching from CCs to HTPs is good for both men and women because the changes in each biomarker in urine samples were the same in men and women. Among all the subjects, subjects aged 20–39 years had the greatest reduction in biomarker residues in urine. The findings of the present study provided useful information for the health risk research of HTPs in China. Full article

Heated tobacco products (HTPs) are novel products that allow users to inhale nicotine by heating (350 °C) reconstituted tobacco rather than combustion (900 °C) as in conventional cigarettes. HTP sticks containing reconstituted tobacco come in various flavours such as menthol, citrus, etc., like electronic cigarette liquids. Thus, the composition of HTP aerosol will also vary according to the flavouring agents added. Overall, the content of toxic chemicals in HTP aerosol appears to be lower than in cigarette smoke. However, the concentrations of more than twenty harmful and potentially harmful constituents have been reported to be higher in HTP aerosol than in cigarette smoke. Further, several toxic compounds not detected in cigarette smoke are also reported in HTP aerosol. Thus, the risks of HTP use remain unknown. Most of the available data on the composition and health effects of mainstream HTP aerosol exposure are generated by the tobacco industry. Few independent studies have reported short-term pathophysiological effects of HTP use. Currently available HTP toxicity data are mainly on the pulmonary and cardiovascular systems. Moreover, there are no long-term toxicity data and, therefore, the claims of the tobacco industry regarding HTPs as a safer alternative to traditional combustible cigarettes are unsubstantiated. Furthermore, HTP aerosol contains the highly addictive substance nicotine, which is harmful to the adolescent brain, developing foetuses, pregnant women, and also adults. Hence, comprehensive studies addressing the safety profiling related to long-term HTP use are warranted. With this background, the following review summarizes the current state of knowledge on HTP toxicity on four broad lines: composition of mainstream HTP aerosol compared to traditional combustible cigarette smoke, biomarkers of HTP exposure, health effects of HTP exposure, and the harm reduction aspect. Full article

Menthol cigarettes have had a profound adverse effect on public health. On 1 June 2020, Massachusetts became the first state to ban the sale of menthol cigarettes. We explored how perceptions of the ban and smoking behaviors changed over time among a group of 27 individuals who smoked menthol cigarettes at our safety-net hospital. In a convergent mixed methods study, we administered questionnaires and interviews simultaneously at two timepoints: 1 month pre-ban and 6 months post-ban. Pre-ban, we assessed perceptions of the ban and anticipated smoking behaviors after the ban. Post-ban, we assessed participants’ actual smoking behaviors and elicited suggestions to avoid unintended consequences that might undermine intended policy effects. Several respondents perceived the Massachusetts ban as positive because it could promote smoking cessation, prevent youth initiation, and mitigate unfair targeting of socioeconomically disadvantaged populations. Others perceived the ban as an overreach of government policy, financially motivated, and unfairly targeting the Black community. Many continued to smoke menthol cigarettes obtained outside Massachusetts. Individuals suggested promoting tobacco treatment for people affected by the ban and a national ban to circumvent out-of-state purchasing of menthol cigarettes. Our findings suggest that in order to be most effective, healthcare systems must promote tobacco treatment and ensure that treatment is accessible to all individuals affected by the ban. Full article

Background: Currently, the research on factors associated with young adults’ discontinuation of e-cigarette use behavior is limited. This study tested the predictors of self-reported e-cigarette abstinence at one-year follow-up among young adult baseline current e-cigarette users. The following variables were tested as predictors: demographics, cigarette smoking, e-cigarette use dependence, e-cigarette use duration, harm perceptions, and preferred aspects of e-cigarette use, including sensations, flavor, and device characteristics. Methods: Data were provided at two time-points one year apart by 435 ethnically diverse young adults (M age = 22.3, SD = 3.1; 63% women) who reported current e-cigarette use at baseline. Results: Approximately 42% of those who reported current e-cigarette use at baseline (i.e., 184 out of 435 participants) reported discontinuation of e-cigarette use at one-year follow-up. Results indicated that higher e-cigarette dependence, longer history of e-cigarette use, lower e-cigarette harm perceptions, greater preference for both menthol and sweet flavors, for open-pod-based devices, and for e-cigarette use sensations such as buzz, taste and smell of flavors, and throat hit at baseline were associated with lower likelihood of e-cigarette use discontinuation at one-year follow-up. Conclusions: Characteristics associated with nicotine (e.g., dependence) and flavors (e.g., taste and smell) appear to drive the continuation/discontinuation of e-cigarette use among young adults. Thus, cessation strategies may need to be developed with a focus on dependence and harm perceptions related to nicotine and flavors. Furthermore, better regulating open-pod-based devices and sweet–menthol flavors may help e-cigarette use prevention. Full article